It has become increasingly popular to use video cameras for surveillance. Typically a video camera is mounted at a location in order to acquire images of the location 24 hours a day. The video camera must hence be capable of acquiring images at very different conditions, such as different light conditions caused by varying sun direction, changing weather conditions, shadows, the indoor lighting being turned on/off, the headlights of a car on a parking lot during the night, different light sources being directed in different directions generating complex illumination of the scene monitored by the camera etc. The video camera should also be capable of acquiring images of a crowed scene with a lot of people or objects moving around or scenes with no or only a few objects in motion.
A problem arising with such video cameras is that it is difficult to configure the image capturing settings of the camera since the camera is used under many different conditions. The person installing the camera may for example only see typical daytime conditions when setting up the camera and the image capturing settings will then be optimized to fit only these conditions.
U.S. Pat. No. 8,111,942 B1 discloses a system for adjusting the settings of a camera. The settings are adjusted by acquiring an image and comparing it to a reference image. The settings are adjusted based on the comparison and a new image is acquired. This procedure may be repeated until an acceptable image is acquired.
The system of U.S. Pat. No. 8,111,942 has a drawback in that several images typically have to be acquired each time the camera is to acquire an image in order to find an appropriate setting. Another drawback is that it is difficult to use this method for optimizing several image setting parameters as this would require several iterations and it would be difficult to account for interdependencies between different image setting parameters. Yet another drawback is that different locations where the camera is mounted might expose the camera to different conditions which implies that it may be difficult to use a single reference image for all conditions and locations to set the image setting parameters. There is thus need for improvements.